Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Swarming Particles

Abstract:
Silver chloride microparticles act as light-driven micromotors that organize into swarms

Swarming Particles

Weinheim, Germany | Posted on April 8th, 2009

A swarm of tiny machines, speeding in concert through the bloodstream to repair an organ or deliver a drug to its target area, microrobots working together to construct a nanotechnological component—although it sounds like science fiction, it is a thoroughly realistic future scenario. Amazing progress has already been made in the production of autonomous nano- and micromotors, but the little machines have continued to lack in team spirit. To complete challenging tasks, the individual machines must communicate and cooperate with each other. Researchers led by Ayusman Sen at Pennsylvania State University (USA) have now introduced silver chloride microparticles that can "swarm" together, almost like living single-celled organisms. As reported in the journal Angewandte Chemie, irradiation with UV light causes the particles to give off "signal substances" that "attract" other particles.

Living cells and organisms are able to exchange information with each other to accomplish tasks as a team. Single-celled slime molds, for example, living in unfavorable conditions thus release a special substance. Neighboring slime molds follow the gradient of this signal substance and aggregate in the form of a multi-celled fruiting body. The silver chloride particles used by Sen's team, which are about 1µm in size, behave in a similar fashion when irradiated with UV light. Silver chloride decomposes under UV light, releasing ions that act as both a propulsion mechanism and signal substance.

This phenomenon is based on diffusiophoresis, the movement of particles along an electrolyte gradient. The silver chloride particles "swim" toward a higher ion concentration. Because of irregularities in the surfaces of the particles and non-uniform irradiation, the degradation of the particles is asymmetric. Different quantities of ions are released in different places on the surface, which results in a local ion gradient around the particles. The particle thus produces its own ion gradient, which propels it at speeds up to 100 µm/s (self-diffusiophoresis). Neighboring sliver chloride particles follow the ion gradient of the solution and "swim" to regions of higher particle density. After several minutes, this results in small, stable "swarms" of particles. Photochemically inactive silicon dioxide particles also react to the ion signal, aggregating around the silver chloride particles.

This system can be used as a nonbiological model for communication between cells. Most importantly though, it represents a new design principle for "intelligent" synthetic nano- or micromachines that can work together as a team.

Author: Ayusman Sen, The Pennsylvania State University, University Park (USA), research.chem.psu.edu/axsgroup/dr_sen.html

Title: Schooling Behavior of Light-Powered Autonomous Micromotors in Water

Angewandte Chemie International Edition 2009, 48, No. 18, 3308-3312, doi: 10.1002/anie.200804704

####

About Angewandte Chemie
Introduced in 1997, Wiley InterScience® (www.interscience.wiley.com) is a leading international resource for scientific, technical, medical and scholarly content.

In June 2008, Wiley InterScience incorporated the online content formerly hosted on Blackwell Synergy to provide access to over 3 million articles across 1400 journals. This massive archive, combined with some 7000 OnlineBooks and major reference works—plus industry leading databases such as The Cochrane Library, and the acclaimed Current Protocols laboratory manuals—make Wiley InterScience one of the world's premiere resources for advanced research.

For more information, please click here

Contacts:
Editorial office:

or
Amy Molnar (US):
or
Jennifer Beal (UK):
or
Alina Boey (Asia):

Copyright © Wiley InterScience

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Beating the heat a challenge at the nanoscale: Rice University scientists detect thermal boundary that hinders ultracold experiments July 28th, 2016

Ageing can drive progress: Population ageing is likely to boost medicine, nanotechnology and robotics, but increase political risks July 27th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

Possible Futures

Beating the heat a challenge at the nanoscale: Rice University scientists detect thermal boundary that hinders ultracold experiments July 28th, 2016

Ageing can drive progress: Population ageing is likely to boost medicine, nanotechnology and robotics, but increase political risks July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

New nontoxic process promises larger ultrathin sheets of 2-D nanomaterials July 27th, 2016

Molecular Machines

New remote-controlled microrobots for medical operations July 23rd, 2016

Pushing a single-molecule switch: An international team of researchers from Donostia International Physics Center, Fritz-Haber Institute of the Max Planck Society, University of Liverpool, and the Polish Academy of Sciences has shown a new way to operate a single-molecule switch July 19th, 2016

Researchers harness DNA as the engine of super-efficient nanomachine: New platform detects traces of everything from bacteria to viruses, cocaine and metals July 10th, 2016

On the path toward molecular robots: Scientists at Japan's Hokkaido University have developed light-powered molecular motors that repetitively bend and unbend, bringing us closer to molecular robots. July 8th, 2016

Nanomedicine

Starpharma initiates new DEP™ drug delivery program with AstraZeneca July 27th, 2016

Scientists test nanoparticle drug delivery in dogs with osteosarcoma July 26th, 2016

The NanoWizard® AFM from JPK is applied for interdisciplinary research at the University of South Australia for applications including smart wound healing and how plants can protect themselves from toxins July 26th, 2016

Accurate design of large icosahedral protein nanocages pushes bioengineering boundaries: Scientists used computational methods to build ten large, two-component, co-assembling icosahedral protein complexes the size of small virus coats July 25th, 2016

Announcements

Beating the heat a challenge at the nanoscale: Rice University scientists detect thermal boundary that hinders ultracold experiments July 28th, 2016

Ageing can drive progress: Population ageing is likely to boost medicine, nanotechnology and robotics, but increase political risks July 27th, 2016

WSU researchers 'watch' crystal structure change in real time: Breakthrough made possible by new Argonne facility July 27th, 2016

Enhancing molecular imaging with light: New technology platform increases spectroscopic resolution by 4 fold July 27th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic